1. Field of the Invention
This invention relates to power supplies, and more particularly to DC to DC converter circuits commonly utilized to energize gaseous discharge tubes in the form of strobe flash lamps.
2. Description of the Prior Art
Prior art DC to DC converter circuits of the type utilized to energize strobe flash lamps are typically designed to operate at a single input voltage. For vehicular applications, such power supplies are typically designed to operate at either one of the following input voltage levels: twelve volts DC, twenty-four volts DC, thirty-six volts DC or forty-eight volts DC. A wholesaler or distributor who supplies vehicular-mounted strobe power supplies must normally carry an inventory of strobe power supply circuits for each of these four distinct and previously incompatible power supply input voltage ratings.
Strobe power supplies for vehicular applications typically include DC to DC converter circuits using a coupled inductor having primary and feedback windings which are controlled by a switching transistor coupled in series with the current flow path of the primary winding. In all cases, it is necessary to miniaturize such power supply circuits to the maximum extent possible to render them compatible with vehicular installations. In addition, the efficiency of these power supply circuits must be as high as possible due to the relatively limited electrical power generating capacity of the vehicles on which such power supply circuits are mounted. As is always the case, the cost of such circuits must be kept as low as possible and the reliability of these circuits which are exposed to extreme environmental conditions must be as high as possible.
From the customer and distributor standpoint, this prior art solution to the numerous problems addressed above has been begrudgingly accepted, but the additional cost and inconvenience caused by the requirement for stocking and using four different input voltage capacity power supplies has long been recognized.